1 /* 2 * CDDL HEADER START 3 * 4 * The contents of this file are subject to the terms of the 5 * Common Development and Distribution License (the "License"). 6 * You may not use this file except in compliance with the License. 7 * 8 * You can obtain a copy of the license at usr/src/OPENSOLARIS.LICENSE 9 * or http://www.opensolaris.org/os/licensing. 10 * See the License for the specific language governing permissions 11 * and limitations under the License. 12 * 13 * When distributing Covered Code, include this CDDL HEADER in each 14 * file and include the License file at usr/src/OPENSOLARIS.LICENSE. 15 * If applicable, add the following below this CDDL HEADER, with the 16 * fields enclosed by brackets "[]" replaced with your own identifying 17 * information: Portions Copyright [yyyy] [name of copyright owner] 18 * 19 * CDDL HEADER END 20 */ 21 22 /* 23 * Copyright (c) 1988 AT&T 24 * All Rights Reserved 25 * 26 * Copyright 2009 Sun Microsystems, Inc. All rights reserved. 27 * Use is subject to license terms. 28 */ 29 30 /* 31 * This file contains the functions responsible for opening the output file 32 * image, associating the appropriate input elf structures with the new image, 33 * and obtaining new elf structures to define the new image. 34 */ 35 #include <stdio.h> 36 #include <sys/stat.h> 37 #include <fcntl.h> 38 #include <link.h> 39 #include <errno.h> 40 #include <string.h> 41 #include <limits.h> 42 #include <debug.h> 43 #include <unistd.h> 44 #include "msg.h" 45 #include "_libld.h" 46 47 /* 48 * Determine a least common multiplier. Input sections contain an alignment 49 * requirement, which elf_update() uses to insure that the section is aligned 50 * correctly off of the base of the elf image. We must also insure that the 51 * sections mapping is congruent with this alignment requirement. For each 52 * input section associated with a loadable segment determine whether the 53 * segments alignment must be adjusted to compensate for a sections alignment 54 * requirements. 55 */ 56 Xword 57 ld_lcm(Xword a, Xword b) 58 { 59 Xword _r, _a, _b; 60 61 if ((_a = a) == 0) 62 return (b); 63 if ((_b = b) == 0) 64 return (a); 65 66 if (_a > _b) 67 _a = b, _b = a; 68 while ((_r = _b % _a) != 0) 69 _b = _a, _a = _r; 70 return ((a / _a) * b); 71 } 72 73 /* 74 * Open the output file and insure the correct access modes. 75 */ 76 uintptr_t 77 ld_open_outfile(Ofl_desc * ofl) 78 { 79 mode_t mode; 80 struct stat status; 81 82 /* 83 * Determine the required file mode from the type of output file we 84 * are creating. 85 */ 86 mode = (ofl->ofl_flags & (FLG_OF_EXEC | FLG_OF_SHAROBJ)) 87 ? 0777 : 0666; 88 89 /* Determine if the output file already exists */ 90 if (stat(ofl->ofl_name, &status) == 0) { 91 if ((status.st_mode & S_IFMT) != S_IFREG) { 92 /* 93 * It is not a regular file, so don't delete it 94 * or allow it to be deleted. This allows root 95 * users to specify /dev/null output file for 96 * verification links. 97 */ 98 ofl->ofl_flags1 |= FLG_OF1_NONREG; 99 } else { 100 /* 101 * It's a regular file, so unlink it. In standard 102 * Unix fashion, the old file will continue to 103 * exist until its link count drops to 0 and no 104 * process has the file open. In the meantime, we 105 * create a new file (inode) under the same name, 106 * available for new use. 107 * 108 * The advantage of this policy is that creating 109 * a new executable or sharable library does not 110 * corrupt existing processes using the old file. 111 * A possible disadvantage is that if the existing 112 * file has a (link_count > 1), the other names will 113 * continue to reference the old inode, thus 114 * breaking the link. 115 * 116 * A subtlety here is that POSIX says we are not 117 * supposed to replace a non-writable file, which 118 * is something that unlink() is happy to do. The 119 * only 100% reliable test against this is to open 120 * the file for non-destructive write access. If the 121 * open succeeds, we are clear to unlink it, and if 122 * not, then the error generated is the error we 123 * need to report. 124 */ 125 if ((ofl->ofl_fd = open(ofl->ofl_name, O_RDWR, 126 mode)) < 0) { 127 int err = errno; 128 129 if (err != ENOENT) { 130 eprintf(ofl->ofl_lml, ERR_FATAL, 131 MSG_INTL(MSG_SYS_OPEN), 132 ofl->ofl_name, strerror(err)); 133 return (S_ERROR); 134 } 135 } else { 136 (void) close(ofl->ofl_fd); 137 } 138 139 if ((unlink(ofl->ofl_name) == -1) && 140 (errno != ENOENT)) { 141 int err = errno; 142 143 eprintf(ofl->ofl_lml, ERR_FATAL, 144 MSG_INTL(MSG_SYS_UNLINK), 145 ofl->ofl_name, strerror(err)); 146 return (S_ERROR); 147 } 148 } 149 } 150 151 /* 152 * Open (or create) the output file name (ofl_fd acts as a global 153 * flag to ldexit() signifying whether the output file should be 154 * removed or not on error). 155 */ 156 if ((ofl->ofl_fd = open(ofl->ofl_name, O_RDWR | O_CREAT | O_TRUNC, 157 mode)) < 0) { 158 int err = errno; 159 160 eprintf(ofl->ofl_lml, ERR_FATAL, MSG_INTL(MSG_SYS_OPEN), 161 ofl->ofl_name, strerror(err)); 162 return (S_ERROR); 163 } 164 165 return (1); 166 } 167 168 169 /* 170 * If we are creating a memory model we need to update the present memory image. 171 * First we need to call elf_update(ELF_C_NULL) which will calculate the offsets 172 * of each section and its associated data buffers. From this information we 173 * can then determine what padding is required. 174 * Two actions are necessary to convert the present disc image into a memory 175 * image: 176 * 177 * o Loadable segments must be padded so that the next segments virtual 178 * address and file offset are the same. 179 * 180 * o NOBITS sections must be converted into allocated, null filled sections. 181 */ 182 static uintptr_t 183 pad_outfile(Ofl_desc *ofl) 184 { 185 Aliste idx1; 186 off_t offset; 187 Elf_Scn *oscn = 0; 188 Sg_desc *sgp; 189 Ehdr *ehdr; 190 191 /* 192 * Update all the elf structures. This will assign offsets to the 193 * section headers and data buffers as they relate to the new image. 194 */ 195 if (elf_update(ofl->ofl_welf, ELF_C_NULL) == -1) { 196 eprintf(ofl->ofl_lml, ERR_ELF, MSG_INTL(MSG_ELF_UPDATE), 197 ofl->ofl_name); 198 return (S_ERROR); 199 } 200 if ((ehdr = elf_getehdr(ofl->ofl_welf)) == NULL) { 201 eprintf(ofl->ofl_lml, ERR_ELF, MSG_INTL(MSG_ELF_GETEHDR), 202 ofl->ofl_name); 203 return (S_ERROR); 204 } 205 206 /* 207 * Initialize the offset by skipping the Elf header and program 208 * headers. 209 */ 210 offset = ehdr->e_phoff + (ehdr->e_phnum * ehdr->e_phentsize); 211 212 /* 213 * Traverse the segment list looking for loadable segments. 214 */ 215 for (APLIST_TRAVERSE(ofl->ofl_segs, idx1, sgp)) { 216 Phdr *phdr = &(sgp->sg_phdr); 217 Os_desc *osp; 218 Aliste idx2; 219 220 /* 221 * If we've already processed a loadable segment, the `scn' 222 * variable will be initialized to the last section that was 223 * part of that segment. Add sufficient padding to this section 224 * to cause the next segments virtual address and file offset to 225 * be the same. 226 */ 227 if (oscn && (phdr->p_type == PT_LOAD)) { 228 Elf_Data * data; 229 size_t size; 230 231 size = (size_t)(S_ROUND(offset, phdr->p_align) - 232 offset); 233 234 if ((data = elf_newdata(oscn)) == NULL) { 235 eprintf(ofl->ofl_lml, ERR_ELF, 236 MSG_INTL(MSG_ELF_NEWDATA), ofl->ofl_name); 237 return (S_ERROR); 238 } 239 if ((data->d_buf = libld_calloc(size, 1)) == 0) 240 return (S_ERROR); 241 242 data->d_type = ELF_T_BYTE; 243 data->d_size = size; 244 data->d_align = 1; 245 data->d_version = ofl->ofl_dehdr->e_version; 246 } 247 248 /* 249 * Traverse the output sections for this segment calculating the 250 * offset of each section. Retain the final section descriptor 251 * as this will be where any padding buffer will be added. 252 */ 253 for (APLIST_TRAVERSE(sgp->sg_osdescs, idx2, osp)) { 254 Shdr *shdr = osp->os_shdr; 255 256 offset = (off_t)S_ROUND(offset, shdr->sh_addralign); 257 offset += shdr->sh_size; 258 259 /* 260 * If this is a NOBITS output section convert all of 261 * its associated input sections into real, null filled, 262 * data buffers, and change the section to PROGBITS. 263 */ 264 if (shdr->sh_type == SHT_NOBITS) 265 shdr->sh_type = SHT_PROGBITS; 266 } 267 268 /* 269 * If this is a loadable segment retain the last output section 270 * descriptor. This acts both as a flag that a loadable 271 * segment has been seen, and as the segment to which a padding 272 * buffer will be added. 273 */ 274 if (phdr->p_type == PT_LOAD) 275 oscn = osp->os_scn; 276 } 277 return (1); 278 } 279 280 /* 281 * Create an output section. The first instance of an input section triggers 282 * the creation of a new output section. 283 */ 284 static uintptr_t 285 create_outsec(Ofl_desc *ofl, Sg_desc *sgp, Os_desc *osp, Word ptype, int shidx, 286 Boolean fixalign) 287 { 288 Elf_Scn *scn; 289 Shdr *shdr; 290 291 /* 292 * Get a section descriptor for the section. 293 */ 294 if ((scn = elf_newscn(ofl->ofl_welf)) == NULL) { 295 eprintf(ofl->ofl_lml, ERR_ELF, MSG_INTL(MSG_ELF_NEWSCN), 296 ofl->ofl_name); 297 return (S_ERROR); 298 } 299 osp->os_scn = scn; 300 301 /* 302 * Get a new section header table entry and copy the pertinent 303 * information from the in-core descriptor. 304 */ 305 if ((shdr = elf_getshdr(scn)) == NULL) { 306 eprintf(ofl->ofl_lml, ERR_ELF, MSG_INTL(MSG_ELF_GETSHDR), 307 ofl->ofl_name); 308 return (S_ERROR); 309 } 310 *shdr = *(osp->os_shdr); 311 osp->os_shdr = shdr; 312 313 /* 314 * If this is the first section within a loadable segment, and the 315 * alignment needs to be updated, record this section. 316 */ 317 if ((fixalign == TRUE) && (ptype == PT_LOAD) && (shidx == 1)) 318 sgp->sg_fscn = scn; 319 320 /* 321 * If not building a relocatable object, remove any of the 322 * following flags, as they have been acted upon and are not 323 * meaningful in the output: 324 * SHF_ORDERED, SHF_LINK_ORDER, SHF_GROUP 325 * For relocatable objects, we allow them to propagate to 326 * the output object to be handled by the next linker that 327 * sees them. 328 */ 329 if ((ofl->ofl_flags & FLG_OF_RELOBJ) == 0) 330 osp->os_shdr->sh_flags &= ~(ALL_SHF_ORDER|SHF_GROUP); 331 332 /* 333 * If this is a TLS section, save it so that the PT_TLS program header 334 * information can be established after the output image has been 335 * initially created. At this point, all TLS input sections are ordered 336 * as they will appear in the output image. 337 */ 338 if ((ofl->ofl_flags & FLG_OF_TLSPHDR) && 339 (osp->os_shdr->sh_flags & SHF_TLS) && 340 (aplist_append(&ofl->ofl_ostlsseg, osp, 341 AL_CNT_OFL_OSTLSSEG) == NULL)) 342 return (S_ERROR); 343 344 return (0); 345 } 346 347 /* 348 * Create the elf structures that allow the input data to be associated with the 349 * new image: 350 * 351 * o define the new elf image using elf_begin(), 352 * 353 * o obtain an elf header for the image, 354 * 355 * o traverse the input segments and create a program header array 356 * to define the required segments, 357 * 358 * o traverse the output sections for each segment assigning a new 359 * section descriptor and section header for each, 360 * 361 * o traverse the input sections associated with each output section 362 * and assign a new data descriptor to each (each output section 363 * becomes a linked list of input data buffers). 364 */ 365 uintptr_t 366 ld_create_outfile(Ofl_desc *ofl) 367 { 368 Sg_desc *sgp; 369 Os_desc *osp; 370 Is_desc *isp; 371 Elf_Data *tlsdata = 0; 372 Aliste idx1; 373 ofl_flag_t flags = ofl->ofl_flags; 374 ofl_flag_t flags1 = ofl->ofl_flags1; 375 size_t ndx; 376 Elf_Cmd cmd; 377 Boolean fixalign = FALSE; 378 int fd, nseg = 0, shidx, dataidx, ptloadidx = 0; 379 380 DBG_CALL(Dbg_basic_create(ofl->ofl_lml)); 381 382 /* 383 * If DF_1_NOHDR was set in map_parse() or FLG_OF1_VADDR was set, 384 * we need to do alignment adjustment. 385 */ 386 if ((flags1 & FLG_OF1_VADDR) || 387 (ofl->ofl_dtflags_1 & DF_1_NOHDR)) { 388 fixalign = TRUE; 389 } 390 391 if (flags1 & FLG_OF1_MEMORY) { 392 cmd = ELF_C_IMAGE; 393 fd = 0; 394 } else { 395 fd = ofl->ofl_fd; 396 cmd = ELF_C_WRITE; 397 } 398 399 /* 400 * If there are any ordered sections, handle them here. 401 */ 402 if ((ofl->ofl_ordered != NULL) && 403 (ld_sort_ordered(ofl) == S_ERROR)) 404 return (S_ERROR); 405 406 /* 407 * Tell the access library about our new temporary file. 408 */ 409 if ((ofl->ofl_welf = elf_begin(fd, cmd, 0)) == NULL) { 410 eprintf(ofl->ofl_lml, ERR_ELF, MSG_INTL(MSG_ELF_BEGIN), 411 ofl->ofl_name); 412 return (S_ERROR); 413 } 414 415 /* 416 * Obtain a new Elf header. 417 */ 418 if ((ofl->ofl_nehdr = elf_newehdr(ofl->ofl_welf)) == NULL) { 419 eprintf(ofl->ofl_lml, ERR_ELF, MSG_INTL(MSG_ELF_NEWEHDR), 420 ofl->ofl_name); 421 return (S_ERROR); 422 } 423 ofl->ofl_nehdr->e_machine = ofl->ofl_dehdr->e_machine; 424 425 DBG_CALL(Dbg_util_nl(ofl->ofl_lml, DBG_NL_STD)); 426 for (APLIST_TRAVERSE(ofl->ofl_segs, idx1, sgp)) { 427 int frst = 0; 428 Phdr *phdr = &(sgp->sg_phdr); 429 Word ptype = phdr->p_type; 430 Aliste idx2; 431 432 /* 433 * Count the number of segments that will go in the program 434 * header table. If a segment is empty, ignore it. 435 */ 436 if (!(flags & FLG_OF_RELOBJ)) { 437 /* 438 * If the program header type belongs to the os range, 439 * the resulting object is ELFOSABI_SOLARIS. 440 */ 441 if ((ptype >= PT_LOOS) && (ptype <= PT_HIOS)) 442 ofl->ofl_flags |= FLG_OF_OSABI; 443 444 if (ptype == PT_PHDR) { 445 /* 446 * If we are generating an interp section (and 447 * thus an associated PT_INTERP program header 448 * entry) also generate a PT_PHDR program header 449 * entry. This allows the kernel to generate 450 * the appropriate aux vector entries to pass to 451 * the interpreter (refer to exec/elf/elf.c). 452 * Note that if an image was generated with an 453 * interp section, but no associated PT_PHDR 454 * program header entry, the kernel will simply 455 * pass the interpreter an open file descriptor 456 * when the image is executed). 457 */ 458 if (ofl->ofl_osinterp) 459 nseg++; 460 } else if (ptype == PT_INTERP) { 461 if (ofl->ofl_osinterp) 462 nseg++; 463 } else if (ptype == PT_DYNAMIC) { 464 if (flags & FLG_OF_DYNAMIC) 465 nseg++; 466 } else if (ptype == PT_TLS) { 467 if (flags & FLG_OF_TLSPHDR) 468 nseg++; 469 } else if (ptype == PT_SUNW_UNWIND) { 470 if (ofl->ofl_unwindhdr) 471 nseg++; 472 } else if (ptype == PT_SUNWDTRACE) { 473 if (ofl->ofl_dtracesym) 474 nseg++; 475 } else if (ptype == PT_SUNWCAP) { 476 if (ofl->ofl_oscap) 477 nseg++; 478 } else if (sgp->sg_flags & FLG_SG_EMPTY) { 479 nseg++; 480 } else if (sgp->sg_osdescs != NULL) { 481 if ((sgp->sg_flags & FLG_SG_PHREQ) == 0) { 482 /* 483 * If this is a segment for which 484 * we are not making a program header, 485 * don't increment nseg 486 */ 487 ptype = (sgp->sg_phdr).p_type = PT_NULL; 488 } else if (ptype != PT_NULL) 489 nseg++; 490 } 491 } 492 493 /* 494 * Establish any processing unique to the first loadable 495 * segment. 496 */ 497 if ((ptype == PT_LOAD) && (ptloadidx == 0)) { 498 ptloadidx++; 499 500 /* 501 * If the first loadable segment has the ?N flag then 502 * alignments of following segments need to be fixed, 503 * plus a .dynamic FLAGS1 setting is required. 504 */ 505 if (sgp->sg_flags & FLG_SG_NOHDR) { 506 fixalign = TRUE; 507 ofl->ofl_dtflags_1 |= DF_1_NOHDR; 508 } 509 } 510 511 shidx = 0; 512 for (APLIST_TRAVERSE(sgp->sg_osdescs, idx2, osp)) { 513 Aliste idx3; 514 int os_isdescs_idx; 515 516 dataidx = 0; 517 518 OS_ISDESCS_TRAVERSE(os_isdescs_idx, osp, idx3, isp) { 519 Elf_Data *data; 520 Ifl_desc *ifl = isp->is_file; 521 522 /* 523 * An input section in the list that has 524 * been previously marked to be discarded 525 * should be completely ignored. 526 */ 527 if (isp->is_flags & FLG_IS_DISCARD) 528 continue; 529 530 /* 531 * At this point we know whether a section has 532 * been referenced. If it hasn't, and the whole 533 * file hasn't been referenced (which would have 534 * been caught in ignore_section_processing()), 535 * give a diagnostic (-D unused,detail) or 536 * discard the section if -zignore is in effect. 537 */ 538 if (ifl && 539 (((ifl->ifl_flags & FLG_IF_FILEREF) == 0) || 540 ((ptype == PT_LOAD) && 541 ((isp->is_flags & FLG_IS_SECTREF) == 0) && 542 (isp->is_shdr->sh_size > 0)))) { 543 Lm_list *lml = ofl->ofl_lml; 544 545 if (ifl->ifl_flags & FLG_IF_IGNORE) { 546 isp->is_flags |= FLG_IS_DISCARD; 547 DBG_CALL(Dbg_unused_sec(lml, 548 isp)); 549 continue; 550 } else { 551 DBG_CALL(Dbg_unused_sec(lml, 552 isp)); 553 } 554 } 555 556 /* 557 * If this section provides no data, and isn't 558 * referenced, then it can be discarded as well. 559 * Note, if this is the first input section 560 * associated to an output section, let it 561 * through, there may be a legitimate reason why 562 * the user wants a null section. Discarding 563 * additional sections is intended to remove the 564 * empty clutter the compilers have a habit of 565 * creating. Don't provide an unused diagnostic 566 * as these sections aren't typically the users 567 * creation. 568 */ 569 if (ifl && dataidx && 570 ((isp->is_flags & FLG_IS_SECTREF) == 0) && 571 (isp->is_shdr->sh_size == 0)) { 572 isp->is_flags |= FLG_IS_DISCARD; 573 continue; 574 } 575 576 /* 577 * The first input section triggers the creation 578 * of the associated output section. 579 */ 580 if (osp->os_scn == NULL) { 581 shidx++; 582 583 if (create_outsec(ofl, sgp, osp, ptype, 584 shidx, fixalign) == S_ERROR) 585 return (S_ERROR); 586 } 587 588 dataidx++; 589 590 /* 591 * Create a new output data buffer for each 592 * input data buffer, thus linking the new 593 * buffers to the new elf output structures. 594 * Simply make the new data buffers point to 595 * the old data. 596 */ 597 if ((data = elf_newdata(osp->os_scn)) == NULL) { 598 eprintf(ofl->ofl_lml, ERR_ELF, 599 MSG_INTL(MSG_ELF_NEWDATA), 600 ofl->ofl_name); 601 return (S_ERROR); 602 } 603 *data = *(isp->is_indata); 604 isp->is_indata = data; 605 606 if ((fixalign == TRUE) && (ptype == PT_LOAD) && 607 (shidx == 1) && (dataidx == 1)) 608 data->d_align = sgp->sg_addralign; 609 610 /* 611 * Save the first TLS data buffer, as this is 612 * the start of the TLS segment. Realign this 613 * buffer based on the alignment requirements 614 * of all the TLS input sections. 615 */ 616 if ((flags & FLG_OF_TLSPHDR) && 617 (isp->is_shdr->sh_flags & SHF_TLS)) { 618 if (tlsdata == 0) 619 tlsdata = data; 620 tlsdata->d_align = 621 ld_lcm(tlsdata->d_align, 622 isp->is_shdr->sh_addralign); 623 } 624 625 #if defined(_ELF64) && defined(_ILP32) 626 /* 627 * 4106312, the 32-bit ELF64 version of ld 628 * needs to be able to create large .bss 629 * sections. The d_size member of Elf_Data 630 * only allows 32-bits in _ILP32, so we build 631 * multiple data-items that each fit into 32- 632 * bits. libelf (4106398) can summ these up 633 * into a 64-bit quantity. This only works 634 * for NOBITS sections which don't have any 635 * real data to maintain and don't require 636 * large file support. 637 */ 638 if (isp->is_shdr->sh_type == SHT_NOBITS) { 639 Xword sz = isp->is_shdr->sh_size; 640 641 while (sz >> 32) { 642 data->d_size = SIZE_MAX; 643 sz -= (Xword)SIZE_MAX; 644 645 data = elf_newdata(osp->os_scn); 646 if (data == NULL) 647 return (S_ERROR); 648 } 649 data->d_size = (size_t)sz; 650 } 651 #endif 652 653 /* 654 * If this segment requires rounding realign the 655 * first data buffer associated with the first 656 * section. 657 */ 658 if ((frst++ == 0) && 659 (sgp->sg_flags & FLG_SG_ROUND)) { 660 Xword align; 661 662 if (data->d_align) 663 align = (Xword) 664 S_ROUND(data->d_align, 665 sgp->sg_round); 666 else 667 align = sgp->sg_round; 668 669 data->d_align = (size_t)align; 670 } 671 } 672 673 /* 674 * Clear the szoutrels counter so that it can be used 675 * again in the building of relocs. See machrel.c. 676 */ 677 osp->os_szoutrels = 0; 678 } 679 } 680 681 /* 682 * Did we use ELF features from the osabi range? If so, 683 * update the ELF header osabi fields. If this doesn't happen, 684 * those fields remain 0, reflecting a generic System V ELF ABI. 685 */ 686 if (ofl->ofl_flags & FLG_OF_OSABI) { 687 ofl->ofl_nehdr->e_ident[EI_OSABI] = ELFOSABI_SOLARIS; 688 ofl->ofl_nehdr->e_ident[EI_ABIVERSION] = EAV_SUNW_CURRENT; 689 } 690 691 /* 692 * Build an empty PHDR. 693 */ 694 if (nseg) { 695 if ((ofl->ofl_phdr = elf_newphdr(ofl->ofl_welf, 696 nseg)) == NULL) { 697 eprintf(ofl->ofl_lml, ERR_ELF, 698 MSG_INTL(MSG_ELF_NEWPHDR), ofl->ofl_name); 699 return (S_ERROR); 700 } 701 } 702 703 /* 704 * If we need to generate a memory model, pad the image. 705 */ 706 if (flags1 & FLG_OF1_MEMORY) { 707 if (pad_outfile(ofl) == S_ERROR) 708 return (S_ERROR); 709 } 710 711 /* 712 * After all the basic input file processing, all data pointers are 713 * referencing two types of memory: 714 * 715 * o allocated memory, ie. elf structures, internal link 716 * editor structures, and any new sections that have been 717 * created. 718 * 719 * o original input file mmap'ed memory, ie. the actual data 720 * sections of the input file images. 721 * 722 * Up until now, the only memory modifications have been carried out on 723 * the allocated memory. Before carrying out any relocations, write the 724 * new output file image and reassign any necessary data pointers to the 725 * output files memory image. This insures that any relocation 726 * modifications are made to the output file image and not to the input 727 * file image, thus preventing the creation of dirty pages and reducing 728 * the overall swap space requirement. 729 * 730 * Write out the elf structure so as to create the new file image. 731 */ 732 if ((ofl->ofl_size = (size_t)elf_update(ofl->ofl_welf, 733 ELF_C_WRIMAGE)) == (size_t)-1) { 734 eprintf(ofl->ofl_lml, ERR_ELF, MSG_INTL(MSG_ELF_UPDATE), 735 ofl->ofl_name); 736 return (S_ERROR); 737 } 738 739 /* 740 * Initialize the true `ofl' information with the memory images address 741 * and size. This will be used to write() out the image once any 742 * relocation processing has been completed. We also use this image 743 * information to setup a new Elf descriptor, which is used to obtain 744 * all the necessary elf pointers within the new output image. 745 */ 746 if ((ofl->ofl_elf = elf_begin(0, ELF_C_IMAGE, 747 ofl->ofl_welf)) == NULL) { 748 eprintf(ofl->ofl_lml, ERR_ELF, MSG_INTL(MSG_ELF_BEGIN), 749 ofl->ofl_name); 750 return (S_ERROR); 751 } 752 if ((ofl->ofl_nehdr = elf_getehdr(ofl->ofl_elf)) == NULL) { 753 eprintf(ofl->ofl_lml, ERR_ELF, MSG_INTL(MSG_ELF_GETEHDR), 754 ofl->ofl_name); 755 return (S_ERROR); 756 } 757 if (!(flags & FLG_OF_RELOBJ)) 758 if ((ofl->ofl_phdr = elf_getphdr(ofl->ofl_elf)) == NULL) { 759 eprintf(ofl->ofl_lml, ERR_ELF, 760 MSG_INTL(MSG_ELF_GETPHDR), ofl->ofl_name); 761 return (S_ERROR); 762 } 763 764 /* 765 * Reinitialize the section descriptors, section headers and obtain new 766 * output data buffer pointers (these will be used to perform any 767 * relocations). 768 */ 769 ndx = 0; 770 for (APLIST_TRAVERSE(ofl->ofl_segs, idx1, sgp)) { 771 Phdr *_phdr = &(sgp->sg_phdr); 772 Os_desc *osp; 773 Aliste idx2; 774 Boolean recorded = FALSE; 775 776 for (APLIST_TRAVERSE(sgp->sg_osdescs, idx2, osp)) { 777 /* 778 * Make sure that an output section was originally 779 * created. Input sections that had been marked as 780 * discarded may have made an output section 781 * unnecessary. Remove this alist entry so that 782 * future output section descriptor processing doesn't 783 * have to compensate for this empty section. 784 */ 785 if (osp->os_scn == NULL) { 786 aplist_delete(sgp->sg_osdescs, &idx2); 787 continue; 788 } 789 if ((osp->os_scn = 790 elf_getscn(ofl->ofl_elf, ++ndx)) == NULL) { 791 eprintf(ofl->ofl_lml, ERR_ELF, 792 MSG_INTL(MSG_ELF_GETSCN), ofl->ofl_name, 793 ndx); 794 return (S_ERROR); 795 } 796 if ((osp->os_shdr = 797 elf_getshdr(osp->os_scn)) == NULL) { 798 eprintf(ofl->ofl_lml, ERR_ELF, 799 MSG_INTL(MSG_ELF_GETSHDR), ofl->ofl_name); 800 return (S_ERROR); 801 } 802 if ((fixalign == TRUE) && sgp->sg_fscn && 803 (recorded == FALSE)) { 804 size_t fndx; 805 Elf_Scn *scn; 806 807 scn = sgp->sg_fscn; 808 if ((fndx = elf_ndxscn(scn)) == SHN_UNDEF) { 809 eprintf(ofl->ofl_lml, ERR_ELF, 810 MSG_INTL(MSG_ELF_NDXSCN), 811 ofl->ofl_name); 812 return (S_ERROR); 813 } 814 if (ndx == fndx) { 815 sgp->sg_fscn = osp->os_scn; 816 recorded = TRUE; 817 } 818 } 819 820 if ((osp->os_outdata = 821 elf_getdata(osp->os_scn, NULL)) == NULL) { 822 eprintf(ofl->ofl_lml, ERR_ELF, 823 MSG_INTL(MSG_ELF_GETDATA), ofl->ofl_name); 824 return (S_ERROR); 825 } 826 827 /* 828 * If this section is part of a loadable segment insure 829 * that the segments alignment is appropriate. 830 */ 831 if (_phdr->p_type == PT_LOAD) { 832 _phdr->p_align = ld_lcm(_phdr->p_align, 833 osp->os_shdr->sh_addralign); 834 } 835 } 836 } 837 return (1); 838 } 839